The subject matter of the present invention includes cosmetic agents comprising two components covalently linked to each other and having functions that differ from one another, the first component being a peptidic linker molecule with high affinity or binding specificity for keratin-containing material and the second component being at least one cosmetic agent consisting of at least one cosmetically active compound known per se or a cosmetic effector molecule for the cosmetic treatment of keratin-containing material.
The combination of the invention finds general use in the cosmetic treatment of parts of the human or animal body that contain keratin and particularly as a hair-treating agent.
The targeted and in terms of quantity and method optimum use of cosmetic products is based on the idea of being able to apply the agents or materials in question in as efficient a manner as possible to the desired parts of the body and to exclude as much as possible other areas of the body.
To achieve this goal, three methods are available in principle. According to one method, the cosmetic agent exhibiting the desired action can be applied to the desired body site locally by means of appropriate mechanical aids, while at the same time covering the body areas with which the cosmetic agent in question is not to come in contact. This method, however, has the drawback that it allows one to reach only the directly accessible parts of the body, that contact with undesirable body sites can practically be difficult to avoid and that the handling of the method is awkward.
According to the second method, it is possible, based on certain chemical and biochemical/physiological properties, to select cosmetic agents that preferentially bind or adhere to certain structures (for example skin, hair, nails). The drawback of these methods is, in particular, that the use of these substances is highly restricted by their chemical nature so that the desired site-specific action of the cosmetic agent in question often does not occur in the hoped-for manner and that the material is not suited for cosmetic use.
As a third possibility, it has recently been proposed to use various antibodies with different specificity for cosmetic agents as vehicles for a targeted application of cosmetic agents. In this manner, by coupling with antibodies, the cosmetic agents are transported to the desired sites.
Such methods have, in particular, the drawback that the preparation of the antibodies is very expensive and that antibodies are relatively large, complicated and biologically active protein units the use of which, as is known, is not without problems from both a biochemical and a physiological standpoint.